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Nike ACG Mountain Fly 2 Low

In production · trail · Trail / Long run · $150

Rugged all-mountain cruiser with React foam and sticky rubber.

Built for trail, long run, at a target pace of 9:00–13:00 /mi on trail.

The spec sheet

Weight
431 g / 15.2 oz
Heel stack
36 mm
Drop
10 mm
Plate
Rock
Cushioning
4 / 5
Energy return
3 / 5
Responsiveness
2 / 5
Rocker
3 / 5
Flexibility
2 / 5
Stability
3 / 5 (5 = most guidance)
Toe-box
Standard
Sizing
True to size
Durability
~500 mi
Price
$150

How it rides

The foam

Nike tuned this midsole soft (4/5 on our cushioning scale). Energy return is moderate — comfortable and predictable rather than bouncy. 36 mm of heel stack is the modern daily-trainer sweet spot — enough foam for long miles without losing contact with the road. Combined, the ride reads as calm at 2/5 responsiveness.

The plate

A rock plate sits between the foam and the outsole to spread the load of sharp stones and roots. It is protection, not propulsion — it does not add pop, but it keeps the underfoot bruising out of long days on technical ground.

The geometry

A tall 10 mm drop tips weight forward off the heel, which usually suits heel strikers and calves that dislike low-drop shoes. The rocker is moderate — enough curve to smooth the roll-through without dictating your footstrike. The forefoot is stiff, so it rolls rather than bends — a lever, not a slipper. Support is light — neutral, with a mildly steady platform.

Fit, sizing & life

The toe-box is standard width — comfortable for most feet without swimming. It fits true to size. Expect roughly 500 miles from the outsole, about $0.30 per mile at $150.

For the foams and plates Nike uses across its line, read the Nike brand guide.

How it compares

Measured against the 542 currently-available shoes in the catalog. The bar shows where this shoe sits in that range.

Weight

431 g / 15.2 oz

156 g heavier than the catalog median of 275 g

Heel stack

36 mm

Level with the catalog median of 36 mm

Drop

10 mm

4 mm higher than the catalog median of 6 mm

Price

$150

10 cheaper than the catalog median of 160

Responsiveness

2 / 5

Catalog median 3 / 5

Cushioning

4 / 5

Catalog median 4 / 5

Energy return

3 / 5

Catalog median 3 / 5

Durability

~500 mi

Catalog median ~400 mi

Within the Nike line it is heavier than the brand's median (295 g / 10.4 oz) and sits taller than its median stack (36 mm).

Closest alternatives

Current shoes with the nearest combination of weight, stack, drop, foam feel and plate.

Salomon XA Pro 3D v9 GTX

359 g / 12.7 oz · 34 mm · 11 mm drop · Rock · $170

Salomon XA Pro 3D v9 GTX: 34 mm heel stack, 11 mm drop, 359 g — specs from independent lab testing.

Nike Wildhorse 10

311 g / 11.0 oz · 38 mm · 10 mm drop · Rock · $140

Cushioned, protective trail workhorse for long dirt days.

Under Armour Infinite Pro

300 g / 10.6 oz · 36 mm · 8 mm drop · Rock · $135

Cushioned trail version of the Infinite platform for mixed terrain.

Asics Gel Venture 11

320 g / 11.3 oz · 36 mm · 10 mm drop · Rock · $80

Asics Gel Venture 11: 36 mm heel stack, 10 mm drop, 320 g — specs from independent lab testing.

Merrell Agility Peak 6 GORE-TEX

300 g / 10.6 oz · 38 mm · 8 mm drop · Rock · $185

Waterproof Agility Peak 6 for wet, cold and sloppy trail days.

Lineage & siblings